Roasting-furnace.



No. 808,293. PATBNTED DEC. ze, 1905.

l P. E. MARGY ROASTING FURNAGE.

APPLICATION FILED JUNE9,1905.

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UNITED STATES e PATENT orrron.

Specification of Letters Patent.

Patented Dec. 26, 1905.

Application led June 9, 1905. Serial No. 264,457.

To all whom it may concern.-

Beit known that I, FRANK E. MARCY, a citizen of the United States, residing at Chicago, in the county ofCook and State of Illinois, have invented certain new and useful Improve- ,ments in Roasting-Furnaces, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part hereof.

My invention has relation to improvements in roasting-furnaces, and it consists in the novel construction and arrangement of parts more fully set forth in the speciiication and pointed out in the claims.

In the drawings, Figure 1 is a middle vertical section of a roasting-furnace, (broken above the bottom hearth,) showing my invention applied thereto. Fig. 2 is a horizontal section on line 2 2 of Fig. I. Fig. 3 is a vertical section on line 3 3 of Fig. 2. Fig. 4 is a sectional detail of the coupling establishing communication between the return-pipe in the shaft and the opposite ends of the distributing pipes or branches in the hollow arms 5 and Fig. 5 is a similar detail of a modiiication, showing the branches coupled to the inlet-section of the pipe of the circulating system.

The object of my invention is to provide a water cooling and circulating system for the rabble shaft and arms of ore-roasting and similar furnaces which shall not only effectively cool said shaft and arms, but accomplish the necessary results without an undue abstraction of the heat units so essential to a complete and effective roasting of the ore charge confined within the furnace.

A further object of my invention is to provide a water-circulating system for a construction of rabble shaft and arms otherwise adapted to be air-cooled, one form of which construction is shown and described in United States Letters Patent No. 786,599, dated April 4, 1905, issued to Charles H. Repath and myself. This patented construction, qualified in the manner presently to be described, represents one of the forms which my present invention may assume, though generically it contemplates a water-circulatingsystem conned within the air-chambers of a'hollow rabble-shaft and hollow rabblearms coupled thereto or within the air-chamber of any hollow rabble apparatus which is a full equivalent thereof and which said watercirculating system serves to cool.

Under my invention a light, rigid, and

otherwise superior construction of rabblel shaft and arms is possible, combining advantages which tend to increase not only the ef- ;[iciency of the furnace as a roaster, but which tend to reduce the running expenses thereof, thereby resulting in essential economy.

In detail the invention may be described as follows: 1

Referring to the drawings, F represents the furnace, which is of the McDougall type, and h the hearths in which the material is treated, the ore dropping from the upper hearth successively through the several hearths during the roasting operation, the hearths being provided, respectively, with the central and marginal openings a b for the passage of the material, as is well understood in the art. Passing centrally through the several hearths is the hollow rotatable rabble-shaft 1, from which radiate the series of hollow rabble-arms 2, extending into the several hearths and carrying rakes or blades 3, by which the material is stirred and successively fed from one hearth to the hearth immediately beneath it,all as well understood in the art. As in the patent above referred to, the rabble-arms are supported by the structural members 4, passed transversely through the walls of the shaft I, to which they are secured in any approved mechanical manner. The cross-section of the structural member is such as to leave air-spaces c between it and the inner walls of the enveloping rabble-arm supported by it, these air spaces or conduits being available for a purpose presentlyto appear. The structural member terminates at its outer end a short distance from the outer end of the rabble-arm to allow for the passage around the member of the water-distributing pipes, to be hereinafter referred to.

Passing into the rabble-shaft, and preferably through the top thereof, is the inlet branch 5 of a water-circulating pipe, said branch extending on one side of the several structural members 4 to the opposite end of the shaft, Where it returns through a bend 6v in the form of a return branch 5 on the opposite side of the several structural members, the said return branch (in Figs. 1 to 4, inclusive).having leading therefrom at points opposite the structural members suitable branch or distributing pipes or coils 7, enveloping the several members 4 throughout the lengthl IOO of the rabble-arms. The connection between the several coils and the return 5 is effected by means of a T or equivalent coupling 8, having a passage leading from the return 5 on one side of a partition Q within the coupling, the water circulating through the coil around the structural member within the pair of arms which envelop it in any one hearth, the water in its circulation returning to the coupling on the opposite side of the partition 9 and continuing upward through the return to the coil enveloping the next succeeding structural member of the next succeeding hearth, and so on till it reaches the dischargenozzle l0, where it discharges into a trough 11, whence it can be conducted to any suitable point, as well understood in the art. Since the shaft is rotatable and the pipe 5 5 rotates with it, it .is necessary in order that a proper joint be effected between the branch 5 and the stuffing-box 12 that the entering end of the pipe be concentric with the axis of rotation of the shaft'. To efl'ect this, the upper end of the branch 5 has a bent portion or elbow 13, Fig. 1, formed therein, this arrangement bringing the terminal of the pipe concentrically with the axis of the shaft and in line with the discharge end of the stationary water-supply pipe 14. The coils or distributing branches 7 are disposed radially, following the structural members outward from the shaft and being confined within the air spaces or conduits c, formed between the members and the inner walls of the rabblearms. The branches 7 practically contact with the surfaces of the structural members for their full length, this contact insuring a positive cooling for the members and the rabble-arms supported by them, but preventing that abnormal absorption of heat units from the charge which is so objectionable and so detrimental inwater-cooled furnaces in which the water circulates directly through the rabble shaft and arms and comes in direct contact with the walls thereof. In the present improvement the circulating medium is confined to the pipes 5 5 7, between which and the walls of theshaft and arms is interposed an envelop of air, this envelop forming a protecting-jaclet against the undue abstraction by the water of heat units from the charge undergoing roasting. On the other hand, the cooling is sufficient to prevent the deterioration of the rabble apparatus from the destructive effects of the heat within the furnace, so that a furnace cooled in the manner here indicated at once develops a maximum amount of efliciency. The pipe 5, while preferably entering the top of the shaft, may enter the bottom, in which case the circulation would be reversed; but such an arrangement would in no wise constitute a departure from my invention. So, too, might the speciiic construction of the coils cr branches be modified without in any wise departing from the nature or spirit of my invention. Of course any equivalent cooling medium might be substituted for water.

The circulation system as herein applied to the rabble shaft and arms thereof generically contemplates a circulation through the coils or distributing-pipes 7 serially in a vertical direction and through a multiple of pipes in a radial direction-that is to say, the water must first pass through a section of the return 5 and one set of coils 7 before it can advance through the next section of said return and the next coil or branch pipe 7, and since each coil 7 has two branches, each extending into its respective rabble-arm, it may be denominated as a multiple branch. The generic idea here shown would in no wise be affected were the branches 7 to lead from the inlet-pipe section 5 instead of the return 5, (in which event the circulation would be through the top set of coils downward through the series instead of upward, as shown, and in which the return would serve as a direct discharge-pipe without lateral branches.) So far as the present invention is concerned, the principle of circulation would be the same were the branches 7 to radiate from the inletpipe section 5 instead of from the return branch 5, and this modification is shown in Fig. 5, where, as shown by the arrows, the circulation would pass downward through the thence upward through the return-pipe p. In either case the inlet and outlet for the cooling medium would be at one end of the circulating system, as is obvious. It is obvious, of course, that the circulating system here shown need not be restricted in its application to furnaces.

K represents the key connecting the rabble-arm to the structural member.

It might be possible to omit the partition 9 from the coupling or connection 8; but in that event the rising (or descending) current would less positively circulate through the multiple branches or sections of the coils 7 that is to say, the circulation through the latter would not be as well defined-but the omission of the partition would constitute no departure from the general nature of the present invention.

Having described my invention, claim is- 1. In a furnace, a hollow rabble-shaft, a pipe having an inlet'branch confined within the shaft for conveying a cooling medium through the shaft in one direction, and a return branch within the shaft coupled to, or forming a continuation of said inlet branch, for conveying the cooling medium in the opposite direction, substantially as set forth.

2. In a furnace, a hollow rabble-shaft and hollow arms therefor, an inlet-pipe leading into the shaft for conveying a cooling mel dium therethrough in one direction, a return what I inlet-pipe p and the several branches 7 ,and

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coupled to said inlet-pipe located within the shaft, and branches or distributing pipes leading from the return and entering the rabble-arms, substantially as set forth.

3. In a furnace having a series of superimposed hearths, hollow rabble-arms operating in said hearths, and suitable pipes coniined within the hollow arms for circulating a cooling medium therethrough, the discharge of said medium being at the inner ends of the rabble-arms, substantially as set forth,

4. In a furnace, a hollow rabble-shaft and hollow arms therefor, an inlet-pipe for conveying a cooling medium into said shaft, a return for said inlet-pipe located in the shaft, a series of branches or distributing-pipes confined in the hollow arms for conveying the cooling medium from the return throu h the arms and returning said medium to t e return-pipe in the shaft, substantially as set forth.

5. In a furnace having a plurality of hearths, a hollow rabble shaft passing through the hearths, hollow arms radiating from the shaft and extending into the several hearths, structural members for the arms having walls spaced a suitable distance from the walls of the arms, an inlet-pipe and return for conveying a cooling medium into and out of the shaft, and a series of branches leading from the return into the arms and in contiguous relation to the structural members for cooling the latter and the hollow arms, substantially as set forth.

6. In a furnace having a plurality of hearths, a hollow rabble shaft passing through the hearths, hollow arms radiatinT from the shaft and extending into the several hearths, structural members located within and supporting the hollow arms and spaced a suitable distance from the walls thereof, an inlet and return pipe passing through the shaft for conveying a cooling medium thereinto, and branches extending from the return into the hollow arms and around the structural members for cooling the latter and the hollow arms, substantially as set forth.

7. In a furnace, a hollow rabble-shaft and hollow arms therefor, an inlet-pipe leading into the shaft for conveying a cooling medium therethrough in one direction, a return coupled to said inlet-pipe located within the shaft and discharging at a point adjacent to the inlet end of the shaft, and means for conducting a coolinfr medium into the hollow arms, substantially as set forth.

8. ln a furnace, a hollow rabble-shaft and hollow arms therefor, and a water-circulating system of pipes located within said shaft and arms and surrounded by the body of air confined within said shaft and arms, substantially as set forth.

9. ln a furnace having a plurality of he arths, a hollow rabble-shaft p assing through the hearths, a series of structural members radiating from the shaft and extending into the several hearths, a series of hollow arms passed over and supported by the structural members and forming air spaces or conduits therewith, an inlet-pipe and a return in the shaft for conveying a cooling medium into and out of said shaft, and a series of branches leading from the return into the conduits of the arms and enveloping the structural menibers within the arms for cooling said members and arms, substantially as set forth.

10. ln a furnace, rabble-arms having coils confined therein for the circulation of a cooling medium, substantially as set forth.

l 1. In a furnace, a circulating system comprising a longitudinally-disposed pipe and series of branches radiating therefrom at intervals, and means for effecting circulation.

through the pipe and branches longitudinally in series and radially through a multiple, substantially as set forth.

12. In a furnace, a circulating system comprising a longitudinally-disposed pipe, and series of branches radiating therefrom at intervals, means for effecting circulation through the pipe and branches longitudinally in series and radially through a multiple, and inlet means and outlet means for thecirculation means at one end of the system, substantially -as set forth.

13. In a furnace, a circulating system comprising a vertically-disposed pipe and series of branches radiating therefrom at intervals, and means for effecting circulation through the pipe and branches vertically in series and radially through a multiple, substantially as set forth.

14. In a furnace, a circulating system comprising a vertically-disposed pipe and series of branches radiating therefrom at intervals, means for effecting circulation through the pipe and branches vertically in series and radially through a multiple, and inlet means and outlet means for the circulation means at one end of the system, substantially as set forth.

15. In a furnace, a hollow rabble-shaft and hollow rabble-arms radiating therefrom at intervals, in combination with a circulating system comprising a water-circulating pipe confined within the shaft, and branches leading therefrom confined within the arms, means for effecting circulation through the pipe and branches vertically in series and radially through a multiple, andinlet means and outlet means for the circulation means at one end of the system, substantially as set forth.

16. In a roasting-furnace, a hollow shaft, hollow rabble-arms on the shaft, means for circulation within the shaft and arms vertically in series, and radially consecutively through a multiple, and inlet means and outlet means for the circulation means at one end of the shaft, substantially as set forth.

17. In a roasting-furnace, a hollow shaft,

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hollow arms on the shaft, means Jfor circulal tions, and distributingpipes leading from tion within the shaft and arms vertically in series, and radially consecutively through a multiple, and inlet means and outlet means for the circulation means at the top of the shaft7 substantially as set forth. y

18. In a furnace, a hollow rabble-shaft and hollow arms therefor, an inlet-pipe section and return-pipe section conned within the shaft for respectively conducting a circulating medium therethrough in opposite direcone of said pipe-sections into the rabblearms for circulating the cooling medium therethrough and hack to the said pipe-section, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

FRANK E. MARCY. Witnesses:

GEORGE BAZ, H. W. DENNIsoN. 

